The present disclosure relates to a gear shaping machine for the manufacture or machining of gears comprising a shaping tool and a shaping head bearing the shaping tool, wherein the shaping head is movable transversely to the shaping direction for the delivering and lifting of the shaping tool to the workpiece.
With such gear shaping machines, the shaping mechanism carries out an oscillating stroke movement through the workpiece, with a toothed arrangement being produced corresponding to the shape of the shaping tool and the path of the shaping tool through the workpiece. The shaping tool and the workpiece rotate around their axes in gear coupled manner in this context. To avoid the shaping tool brushing against the workpiece in the reverse stroke, the shaping tool is lifted in the cycle of the stroke movement in the reverse stroke and is delivered again in the working stroke, for which purpose the shaping head bearing the shaping tool is movable transversely to the shaping direction.
With known gear shaping machines, the lifting and delivery of the shaping tool usually takes place via a cam rotating continuously and gear coupled to the stroke drive as well as via hydraulic or resilient restoring elements. Such a gear shaping machine is e.g. known from DE 16 27 370. The shape of the cam substantially determines the path of the shaping tool.
It is disadvantageous in this known device that the lifting path in the reverse stroke of the shaping tool cannot be varied without changing the cam. This is important because a smaller lifting path is required for the finish machining than for the rough machining to reduce the dynamic forces and thus to improve the smooth running of the gear shaping machine. A change of the cam is also required on the conversion of the manufacturing process from internal gears to external gears, and vice versa, because the lifting direction changes in each case. A complicated toggle system is therefore known from DE 38 09 802 in which the toggle, which is adjustable in its length, is in communication with the cam which determines the path of the shaping tool. The lifting path can thus be mechanically influenced at least in part by setting the length of the toggle.
However, in the working stroke, the shaping tool must be guided on an exact path which must correspond to the required tooth flank direction. This can be cylindrical, spherical or conical or can be composed of a combination of these possibilities. Since, however, the path of the shaping tool in known gear shaping machines is still determined by the shape of the cam, a change of the cam is also necessary to generate different tooth flank directions and on gear corrections.
It is therefore the underlying object of the present disclosure to provide a gear shaping machine in which the shaping tool can be guided in any desired adjustable path both in the working stroke and in the reverse stroke. Gear errors caused by vibrations and elasticities of the machine should moreover be corrected.